+static BOOL
+tls_refill(unsigned lim)
+{
+int error;
+int inbytes;
+
+DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl,
+ ssl_xfer_buffer, ssl_xfer_buffer_size);
+
+if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
+inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer,
+ MIN(ssl_xfer_buffer_size, lim));
+error = SSL_get_error(server_ssl, inbytes);
+alarm(0);
+
+/* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been
+closed down, not that the socket itself has been closed down. Revert to
+non-SSL handling. */
+
+if (error == SSL_ERROR_ZERO_RETURN)
+ {
+ DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
+
+ receive_getc = smtp_getc;
+ receive_getbuf = smtp_getbuf;
+ receive_get_cache = smtp_get_cache;
+ receive_ungetc = smtp_ungetc;
+ receive_feof = smtp_feof;
+ receive_ferror = smtp_ferror;
+ receive_smtp_buffered = smtp_buffered;
+
+ if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN)
+ SSL_shutdown(server_ssl);
+
+ sk_X509_pop_free(server_static_cbinfo->verify_stack, X509_free);
+ SSL_free(server_ssl);
+ SSL_CTX_free(server_ctx);
+ server_static_cbinfo->verify_stack = NULL;
+ server_ctx = NULL;
+ server_ssl = NULL;
+ tls_in.active = -1;
+ tls_in.bits = 0;
+ tls_in.cipher = NULL;
+ tls_in.peerdn = NULL;
+ tls_in.sni = NULL;
+
+ return FALSE;
+ }
+
+/* Handle genuine errors */
+
+else if (error == SSL_ERROR_SSL)
+ {
+ ERR_error_string(ERR_get_error(), ssl_errstring);
+ log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring);
+ ssl_xfer_error = TRUE;
+ return FALSE;
+ }
+
+else if (error != SSL_ERROR_NONE)
+ {
+ DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
+ ssl_xfer_error = TRUE;
+ return FALSE;
+ }
+
+#ifndef DISABLE_DKIM
+dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
+#endif
+ssl_xfer_buffer_hwm = inbytes;
+ssl_xfer_buffer_lwm = 0;
+return TRUE;
+}
+
+